>So, is it a syntactic feature inherited from XML not to care about the
>order of attributes?
yes -- though citing an authoritative source for the XML part of
this answer was harder than I expected.
It turns out that this may be SGML lore. The XML specification
http://www.w3.org/TR/1998/REC-xml-19980210 is silent on the
question of whether order of attributes is or is not significant.
One of the expected results of the XML Information Set specification
is to state where order is and is not significant.
The latest XML Information Set working draft
http://www.w3.org/TR/1999/WD-xml-infoset-19990517 does in fact say:
2.2.1. Elements: Required Properties
An element information item must have the following properties
available in some form:
...
4.An unordered set of attribute information items, one for each
of the attributes (specified or defaulted) for this element.
(Of course, the XML Information Set specification also says that
the list of children element information items *is* ordered, and
RDF discards this order information).
-Ralph R. Swick
W3C/MIT